ity 14 Standard Normal Distribution 3. Suppose that family incomes in a town are normally distributed with a mean of $1200 and a standard deviation of $600 per month Verbal scores on the GRE are normally distributed with mean What is the probability that a family has an income: a . More than $2, 250? 1 = 500 and a standard deviation of 0 = 100. If a student scored 400, what percent of those who took the test ranked: a. Higher than she did ( >400) ? . b. Higher than 580? b. Less than $1, 400? c. Between 420 and 620? c. Between $1400 and $2250? If IQ scores are normally distributed with a mean of u = 100 and a standard deviation of O = 5, what is the probability that a person chosen at random will have an IQ score: a . Greater than 110? b . Less than 90? c. Between 90 and 110